package com.atguigu.day08;

import com.atguigu.bean.WaterSensor;
import com.atguigu.function.WaterSensorMapFunction;
import org.apache.flink.api.common.state.ListState;
import org.apache.flink.api.common.state.ListStateDescriptor;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.KeyedProcessFunction;
import org.apache.flink.util.Collector;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Felix
 * @date 2024/9/21
 * 该案例演示了键控状态-列表状态
 * 需求：针对每种传感器输出最高的3个水位值
 */
public class Flink03_KeyedState_ListState {
    public static void main(String[] args) throws Exception {
        //TODO 1.准备环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        //TODO 2.设置并行度
        env.setParallelism(1);
        //TODO 3.从指定的网络端口读取数据
        DataStreamSource<String> socketDS = env.socketTextStream("hadoop102", 8888);
        //TODO 4.对流中数据进行类型转换    String->WaterSensor
        SingleOutputStreamOperator<WaterSensor> wsDS = socketDS.map(new WaterSensorMapFunction());
        //TODO 5.按照传感器id进行分组
        KeyedStream<WaterSensor, String> keyedDS = wsDS.keyBy(WaterSensor::getId);
        //TODO 6.对分组后的数据进行处理
        SingleOutputStreamOperator<String> processDS = keyedDS.process(
                new KeyedProcessFunction<String, WaterSensor, String>() {
                    //声明键控状态
                    ListState<Integer> vcListState;

                    //在open中对键控状态进行初始化
                    @Override
                    public void open(Configuration parameters) throws Exception {
                        ListStateDescriptor<Integer> listStateDescriptor
                                = new ListStateDescriptor<Integer>("vcListState", Integer.class);
                        vcListState = getRuntimeContext().getListState(listStateDescriptor);
                    }

                    @Override
                    public void processElement(WaterSensor ws, KeyedProcessFunction<String, WaterSensor, String>.Context ctx, Collector<String> out) throws Exception {
                        //获取当前水位值
                        Integer curVc = ws.getVc();
                        //将当前水位放到状态中
                        vcListState.add(curVc);
                        //对状态中的数据进行排序
                        List<Integer> vcList = new ArrayList<>();
                        for (Integer vc : vcListState.get()) {
                            vcList.add(vc);
                        }
                        vcList.sort((o1, o2) -> o2 - o1);
                        //判断集合中元素的个数 是否大于3
                        if(vcList.size() > 3){
                            vcList.remove(3);
                        }
                        out.collect("传感器id为" + ws.getId() + ",最大的3个水位值=" + vcList.toString());
                        //将list更新状态中
                        vcListState.update(vcList);
                    }
                }
        );
        //TODO 7.打印
        processDS.printToErr();
        //TODO 8.提交作业
        env.execute();

    }
}
